Fix clang errors

- structs used in emplace_back now have defined constructor
- removed dead code from ensure

Testing done:
- CI tests are passing
- UTs are passing

Signed-off-by: Szymon Dompke <szymon.dompke@intel.com>
Change-Id: I3f56a3796e45d608c7a5d3da1f8c2d674d62f567
diff --git a/src/metric_value.hpp b/src/metric_value.hpp
index d01ac4e..6c1d3da 100644
--- a/src/metric_value.hpp
+++ b/src/metric_value.hpp
@@ -9,4 +9,10 @@
     std::string metadata;
     double value;
     uint64_t timestamp;
+
+    MetricValue(std::string_view idIn, std::string_view metadataIn,
+                double valueIn, uint64_t timestampIn) :
+        id(idIn),
+        metadata(metadataIn), value(valueIn), timestamp(timestampIn)
+    {}
 };